RT Journal Article
SR Electronic
T1 Microtubules originate asymmetrically at the somatic Golgi and are guided via Kinesin2 to maintain polarity within neurons
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 846832
DO 10.1101/846832
A1 Amrita Mukherjee
A1 Paul Brooks
A1 Fred Bernard
A1 Antoine Guichet
A1 Paul T. Conduit
YR 2020
UL http://biorxiv.org/content/early/2020/05/19/846832.abstract
AB Neurons contain polarised microtubule arrays essential for neuronal function. How microtubule nucleation and polarity are regulated within neurons remains unclear. We show that γ-tubulin localises asymmetrically to the somatic Golgi within Drosophila neurons. Microtubules originate from the Golgi with an initial growth preference towards the axon. Their growing plus ends also turn towards and into the axon, adding to the plus-end-out microtubule pool. Any plus ends that reach a dendrite, however, do not readily enter, maintaining minus-end-out polarity. Both turning towards the axon and exclusion from dendrites depend on Kinesin-2, a plus-end-associated motor that guides growing plus ends along adjacent microtubules. We propose that Kinesin-2 engages with a polarised microtubule network within the soma to guide growing microtubules towards the axon; while at dendrite entry sites engagement with microtubules of opposite polarity generates a backward stalling force that prevents entry into dendrites and thus maintains minus-end-out polarity within proximal dendrites.Competing Interest StatementThe authors have declared no competing interest.